A&PII Exam 1 Practice

A 68-year-old woman presents to the emergency center with shortness of breath, light-headedness, and chest pain described as like "an elephant sitting on her chest". She is diagnosed with myocardial infarction. She is given oxygen and aspirin to chew. Her rate is 30 beats/min. By looking at the ECG, the ventricular depolarization takes longer to appear after the atrial depolarization. In other words, this patient has been diagnosed with a complete heart block, probably as a result of her myocardial infarction. The patient is taken to the intensive care unit for stabilization, and plans are made for pacemaker insertion. -Which pacemaker is most likely to have been damaged? -Why does the patient have bradycardia?

- AV node -the Purkinje fibers became the pacemaker for the heart

Mr. Langley is telling his friend about his recent visit to his doctor for a checkup. During his story, he mentions that the ECG revealed that he had a defective mitral valve and a heart murmur. Mr. Langley apparently misunderstood some of what the doctor explained to him about the diagnostic process. What has he misunderstood?

- ECG gives the electrical pathway of the heart - murmurs can be heard with a stethoscope

Alan Forsythe, a middle-aged college professor from Boston, is in the Swiss Alps studying astronomy during his sabbatical leave. He has been there for two days and plans to stay the entire year. However, he notices that he is short of breath when he walks up steps and tires easily with any physical activity. His symptoms gradually disappear, and after two months he feels fine. Upon returning to the United States, he has a complete physical exam and is told that his erythrocyte count is higher than normal. (a) Attempt to explain this finding. (b) Will his RBC count remain at this higher-than-normal level? Why or why not?

- decrease oxygen, increase EPO to increase oxygen - no, decrease EPO, decrease RBC

Mary Anne is taking a calcium channel blocking drug. What effect on her stroke volume (SV) would you expect this medication to have?

- decreased stroke volume - less Ca2+ - shorter plateau phase

Mrs. Johnson is brought to the emergency room after being involved in an auto accident. She is hemorrhaging and has a rapid, thread pulse, but her blood pressure is still within normal limits. Describe the compensatory mechanisms that are acting to maintain her blood pressure in the face of blood loss.

- increases heartbeat to compensate for decreased stroke volume - angiotensin II is being produced - ADH released - aldosterone released

Mary Healy, a young woman with severe vaginal bleeding is admitted to the emergency room. She is three months pregnant, and the physician is concerned about the volume of blood she is losing. (a) What type of transfusion will be probably be given to this patient? (b) What blood tests will be performed before starting the transfusion?

-whole blood -blood typing test

Name the five phases of the cardiac cycle:

1.) ventricular filling 2.) isovolumetric contraction 3.) ventricular ejection 4.) isovolumetric relaxation 5.) atrial relaxation and ventricular filling

What is the end-diastolic volume?

130mL

What is the end-systolic pressure?

60mL

What other hormone will increase water absorption from the kidney?

ADH

During the first phase, the blood entering the heart comes from where?

AV valves

During the second and the fourth phases, the:

AV valves and semilunar valves closed

During the third phase, the:

AV valves closed, semilunar valves open

During the fifth phase, what happens to the valves?

AV valves open, semilunar valves closed

During the first and fifth phases, the:

AV valves open, semilunar valves closed

The threshold for the action potential in the SA node is at -40mV. What channel opens, causing further depolarization?

Ca2+ gated channel

What are the EDV and ESV normal values?

EDV= 130mL ESV= 60mL

What is the HPc at the beginning of the capillary? At the end? Explain.

HPc= 35 HPc=16 fluid is coming out, less force exerted against vessels

Which ion first depolarizes the autorhythmic cells?

Na+

State the ion voltage-gated channels responsible for the following stages of the action potential in cardiac contractile cells: Depolarization: __________ Plateau: ____________________ Repolarization: __________

Na+ Ca2+ and K+ K+

The main effect of aldosterone is _________________________, which increases blood volume because water follows.

Na+ reabsorption

A healthy 23-year-old medical student is participating in a cardiac echocardiography study. During the isovolumetric contraction phase of the cardiac cycle, which of the following findings takes place?

The volume in the ventricles equals 130mL

Define stroke volume (SV). What is the normal value?

amount of blood pumped in one heartbeat, 70mL

Define cardiac output (CO). What is the normal value?

amount of blood pumped in one minute, 5.25L

During the fifth phase, where is blood entering the ventricles?

atria and ventricles

P-Q segment represents:

atria contracting

P wave represents:

atrial depolarization

What neural pathways regulate arterial pressure?

baroreceptors

In a capillary, what is equivalent to hydrostatic pressure?

blood pressure

The influx of which ion accounts for the plateau phase?

calcium

The action potentials spread from the autorhythmic cells of the intrinsic conduction system (electrical event) to the ___________________ cells. The resulting mechanical events cause a heartbeat.

contractile

Factors that increase blood pressure:

decreased arterial diameter increased stroke volume increased cardiac output increased sympathetic stimulation increased plasma ADH

Excessive vaginal stimulation can be caused by severe depression. How would this be reflected in a routine physical examination?

decreased heart rate

During the third phase, what happens to ventricular volume?

decreases with pressure

During inspiration, pressure __________________ in the thoracic cavity and ___________________ in the abdominal cavity. This results in an upward "sucking" effect that pulls blood toward the heart.

decreases, increases

During the fourth phase, are ventricles in diastole or systole?

diastole

Relaxation of heart muscles:

diastole

Bulk fluid flow causes __________________ at the arterial end and ______________________ at the venous end of the capilarry.

filtration, reabsorption

Osmotic (or colloid osmotic) pressure in the capillaries is ____________ compared to the interstitium

higher

Which of the following is the least expected outcome of the RAA (renin-angiotensin-aldosterone) system?

increase the blood viscosity

Factors that decrease blood pressure:

increased parasympathetic stimulation decreased blood volume decreased plasma epinephrine decreased blood viscosity decreased plasma angiostensin

During the first phase, what happens to ventricular volume?

increases

Net osmotic pressure tends to move fluid ___________ the capillary:

into

The mitral valve connects:

left atrium and left ventricle

The aortic semilunar valve connects:

left ventricle and aortic artery

What is so special about the plateau phase?

longer plateau = stronger contraction

A young child is diagnosed as having acute lymphocytic leukemia. Her parents cannot understand why infection is a major problem for Janie when her WBC is so high. Can you provide an explanation for Janie's parents?

lymphocytes are immature and confer no immunity

The central cardiac control region is in the _______________ of the brain

medulla oblongata

Net hydrostatic pressure tends to move fluid _________ the capillary:

out

How would inhibition of ACE decrease blood pressure?

preventing the formation of angiotensin II

Freshly oxygenated blood enters the heart through the _______________________ and is pumped out the ___________________.

pulmonary veins, left ventricle

The tricuspid valve connects:

right atrium and right ventricle

The pulmonary semilunar valve connects:

right ventricle and pulmonary trunk

Contraction of heart muscles:

systole

During the first phase, are the atria in diastole or systole?

systole

An abnormally fast heart rate (over 100 bpm) is called:

tachycardia

Why would stroke volume increase when heart rate slows down?

to maintain cardiac output

Name four effects of angiostensin:

vasoconstriction release aldosterone activate thirst center release of ADH

S-T segment represents:

ventricles contracting

QRS complex represents:

ventricular depolarization

Q-T interval represents:

ventricular depolarization and repolarization

T wave represents:

ventricular relaxation

During the second phase, what is happening to ventricular volume and pressure?

volume is constant, pressure increases